STUDY OF THE INFLUENCE OF NUTRIENT SUBSTRATES CONTAINING BIOLOGICALLY ACTIVE SUBSTANCES OF BACTERIA ON INDIVIDUAL SIGNS AND FACTORS OF PATHOGENICITY OF MICROORGANISMS

Abstract

The purpose of the research: based on the use of biologically active substances of microorganisms, to develop highly productive nutrient media for the cultivation of highly demanding bacteria. Research methods involved obtaining ultrasonic disintegrates of microbial suspensions of S. epidermidis, P. aeruginosa with an optical density of 10,0 units on the McFarland scale (Densi-La-Meter device) using a G3-109 generator (40,0 kHz, 6 hours). To study the influence of disintegrants on certain signs and factors of pathogenicity of microorganisms (shape, edges, convexity, size of colonies and pigment formation), ultrasonic disintegrant of S. epidermidis or P. aeruginosa in the amount of 20% was added to nutrient agar. Cultures of experimental microorganisms (S. aureus, P. aeruginosa), which were grown on nutrient agar with or without the addition of disintegrant, were cultivated in aerobic conditions for 1, 2, 3, 5, and 21 days at a temperature of (37 ± 1) ºС. Research results. When growing microbial cells of P. aeruginosa on nutrient agar with their own ultrasonic disintegrates, an increase in the production of pyocyanin pigment was noted (day 1, day 5 of the experiment). Cultivation of P. aeruginosa on media with the addition of ultrasonic disintegrates of S. epidermidis was accompanied by inhibition of pyocyanin (more pronounced at 1 and 2 days, less pronounced at 3 days). Incubation of staphylococcus on nutrient agar with ultrasonically disintegrated S. epidermidis resulted in inhibition of S. aureus pigment after daily exposure and its recovery after two-day exposure. When comparing ultrasonic disintegrates of P. aeruginosa with disintegrates of S. epidermidis, differences were established regarding the enhancement or inhibition of pigments of pathogens. The same in both studied nutrient substrates, which contain biologically active substances of P. aeruginosa or S. epidermidis, was the presence of influencing factors in a limited amount relative to the stimulation / inhibition of pigment formation of microorganisms, or they lost their activity in relation to selected bacterial characteristics over a certain period of time. The presented results can be used in two directions: the development of candidate drugs based on biologically active substances of indigenous microflora, which will make it possible to influence the formation of microbial communities with given properties and suppress the pathogenicity factors of the causative agents of bacterial infections, and the production of nutrient media using, as growth factors, biologically active substances of microorganisms for the cultivation of highly fastidious bacteria.